NativeLsl_push_sample_ltp typedef
        NativeLsl_push_sample_ltp =
     Int32 Function(lsl_outlet out, Pointer<Int64>  data, Double timestamp, Int32 pushthrough)
    
    
    
Implementation
typedef NativeLsl_push_sample_ltp =
    ffi.Int32 Function(
      lsl_outlet out,
      ffi.Pointer<ffi.Int64> data,
      ffi.Double timestamp,
      ffi.Int32 pushthrough,
    );